*4.10. Water and Oxygen Barrier Properties of CS/PVOH/HNT and CS/PVOH/TO@HNT Films*

For the evaluation of the water vapor transmission rate (WVTR) of CS/PVOH/HNT and CS/PVOH/TO@HNT films, a hand-made apparatus was used according to the ASTM E96/E 96M-05 method [66]. According to the methodology described extensively in previous reports [17,40–42,66] experiments were carried out inside thermostated chamber at <sup>38</sup> ◦C and constant 95% RH. Water vapor transmission rate WVTR (g·cm−<sup>2</sup> ·s −1 ) and water vapor diffusion coefficient D (cm<sup>2</sup> ·s −1 ) were estimated according to Equations (2) and (3) respectively as they reported to number [50] referenced paper and based on the theory described in this paper [67].
